Projects

The Sortostat is a microfluidic chemostat integrated with a cell sorter. My project consists of demonstrating the sortostat's chemostat functionality, a technique rarely seen in microfluidics. Chemostasis must first be demonstrated before any meaningful demonstration of the sortostat's sorting capabilities can be shown. The sortostat's sorting ability is limited by the extent to which it can make optical descriminations between cells. Therefore, in order to demonstrate its sorting ability, two visually different populations of cells will be grown to steady state after which sorting is initiated. If successful the populations will clearly diverge in number, the one sorted against will diminish well below its steady state level and the one preserved should rise by the same amount that the other falls. The total population of cells in the chemostat should be conserved in the end if chemostasis was maintained throughout sorting.

Currently troubleshooting problems: i) Cell Death after 3-4 days. This problem has not been an issue for the past few runs that lasted over 300 hours. We initially thought the cell death was due to oxygen depletion however if this was the case we'd expect to see this more consistantly. and ii) Inaccurate cell counts due to poor image processing. There is still much to be done to resolve this issue. Perhaps using software such as Cell Profiler will help to achieve more accurate cell counts.

Evaluate the response of populations of E.Coli cells containing engineered genetic circuits (http://parts.mit.edu) to particular selective pressures using the Sortostat.